JP4019284B2 - Surface emitting device and method for manufacturing the same - Google Patents

Description

  The present invention relates to a surface emitting device and a method for manufacturing the same.

Since the surface emitting semiconductor laser has a smaller element volume than the conventional edge emitting semiconductor laser, the electrostatic breakdown voltage of the element itself is low. For this reason, in the mounting process, the element may be damaged by static electricity applied from a machine or an operator. In particular, a surface-emitting type device such as a surface-emitting type semiconductor laser has a certain level of resistance to a forward bias voltage, but has a low resistance to a reverse bias voltage, and the device is destroyed when a reverse bias voltage is applied. Sometimes. Usually, in the mounting process, various measures are taken to remove static electricity, but these measures have limitations.
JP 2004-6548 A

  An object of the present invention is to prevent electrostatic breakdown and improve reliability in a surface-emitting type device and a manufacturing method thereof.

The surface-emitting type device according to the present invention is
A rectifying unit including a substrate and a first semiconductor layer formed above the substrate;
A first conductivity type second semiconductor layer formed above the rectifying unit; an active layer formed above the second semiconductor layer; and a second conductivity type second semiconductor layer formed above the active layer. A light emitting unit including three semiconductor layers;
Including
The rectifying unit and the light emitting unit are electrically connected in parallel,
The rectifying unit has a rectifying action in a direction opposite to that of the light emitting unit.

  According to this surface emitting device, even when a reverse bias voltage is applied to the light emitting unit, a current flows through the rectifying unit connected in parallel with the light emitting unit. Thereby, the electrostatic breakdown voltage with respect to the reverse bias voltage of the surface emitting device can be remarkably improved. Therefore, electrostatic breakdown in the mounting process or the like can be prevented, so that handling is excellent and reliability can be improved.

  In the present invention, other specific objects (hereinafter referred to as “B”) formed above a specific object (hereinafter referred to as “A”) are defined as B directly formed on A and A And B formed via the others on A. Further, in the present invention, forming B above A includes a case where B is formed directly on A and a case where B is formed on A via another on A.

  In the present invention, the “light absorption layer” is a concept including a depletion layer.

In the surface-emitting type device according to the present invention,
The photodetecting portion may include a substrate, a light absorbing layer formed above the substrate, and a contact layer formed above the light absorbing layer.

In the surface-emitting type device according to the present invention,
A substrate connection electrode electrically connected to the substrate;
First, second, and third electrodes that are electrically connected to the first, second, and third semiconductor layers, respectively.
The substrate is of a first conductivity type;
The first semiconductor layer is of a second conductivity type;
The substrate connection electrode and the third electrode are electrically connected,
The first electrode and the second electrode may be electrically connected.

In the surface-emitting type device according to the present invention,
The rectifying unit may include a fourth semiconductor layer formed between the substrate and the first semiconductor layer.

In the surface-emitting type device according to the present invention,
Having first, second, third, and fourth electrodes electrically connected to the first, second, third, and fourth semiconductor layers, respectively;
The first semiconductor layer is of a second conductivity type;
The fourth semiconductor layer is of a first conductivity type;
The first electrode and the second electrode are electrically connected,
The third electrode and the fourth electrode may be electrically connected.

In the surface-emitting type device according to the present invention,
A light detection unit including the substrate, a light absorption layer formed above the substrate, and a contact layer formed above the light absorption layer;
The light detection unit has another contact layer formed between the substrate and the light absorption layer,
The contact layer is formed in the same process as the first semiconductor layer,
The other contact layer may be formed in the same process as the fourth semiconductor layer.

In the surface-emitting type device according to the present invention,
A capacitance adjusting layer may be formed between the substrate and the first semiconductor layer.

In the surface-emitting type device according to the present invention,
The light emitting unit may be formed vertically above at least a part of the rectifying unit.

In the surface-emitting type device according to the present invention,
The light emitting unit functions as a surface emitting semiconductor laser,
The second semiconductor layer and the third semiconductor layer may be mirrors.

In the surface-emitting type device according to the present invention,
The light emitting unit functions as a surface emitting semiconductor laser,
The second semiconductor layer and the third semiconductor layer are mirrors;
The light detection unit functions as a monitor photodiode for the surface emitting semiconductor laser,
A lens part may be formed above the contact layer.

A method for manufacturing a surface-emitting device according to the present invention includes:
Forming a first semiconductor layer above the substrate; forming a first conductivity type second semiconductor layer above the first semiconductor layer; and forming an active layer above the second semiconductor layer. Forming a semiconductor multilayer film, comprising: a step; forming a second conductive type third semiconductor layer above the active layer;
The semiconductor is formed such that a rectifying unit including the substrate and the first semiconductor layer, and a light emitting unit including the second semiconductor layer, the active layer, and the third semiconductor layer are formed. Patterning the multilayer film;
Including
The rectifying unit and the light emitting unit are arranged to be electrically connected in parallel,
The rectifying unit is formed to have a rectifying action in a direction opposite to that of the light emitting unit.

In the method for manufacturing the surface-emitting type device according to the present invention,
In the step of forming the semiconductor multilayer film,
Forming a contact layer in the same process as the first semiconductor layer;
The step of forming the semiconductor multilayer film includes the step of forming a light absorption layer above the substrate before the step of forming the contact layer,
The step of patterning the semiconductor multilayer film includes:
A light detection unit including the substrate, the light absorption layer, and the contact layer may be formed.

In the method for manufacturing the surface-emitting type device according to the present invention,
The step of forming the semiconductor multilayer film includes a step of forming a fourth semiconductor layer above the substrate before the step of forming the first semiconductor layer,
The step of patterning the semiconductor multilayer film includes:
The rectifying unit having the fourth semiconductor layer may be formed.

In the method for manufacturing the surface-emitting type device according to the present invention,
In the step of forming the semiconductor multilayer film,
Forming a contact layer in the same process as the first semiconductor layer;
Forming another contact layer in the same process as the fourth semiconductor layer;
The step of forming the semiconductor multilayer film includes a step of forming a light absorption layer above the other contact layer before the step of forming the contact layer,
The step of patterning the semiconductor multilayer film includes:
A light detection unit including the contact layer, the light absorption layer, and the other contact layer may be formed.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. 1. First embodiment 1-1. First, the surface emitting device 100 according to the first embodiment will be described.

  1 is a cross-sectional view taken along the line II of FIG. 2, and FIG. 2 is a plan view schematically showing the surface-emitting type device 100. As shown in FIG. FIG. 3 is a circuit diagram of the surface-emitting type device 100.

  As shown in FIGS. 1 and 2, the surface-emitting type device 100 includes a rectifying unit 120 and a light emitting unit 140. In the present embodiment, a case where the rectifying unit 120 functions as a junction diode (including a Zener diode) and the light emitting unit 140 functions as a surface emitting semiconductor laser will be described.

  The rectifying unit 120 includes a substrate 101, a capacitance adjustment layer 112 formed above the substrate 101, and a first semiconductor layer 114 formed above the capacitance adjustment layer 112. The rectifying unit 120 has a rectifying action. As the substrate 101, for example, a first conductivity type (for example, n-type) GaAs substrate or the like can be used. The substrate 101 supports the rectifying unit 120 and the light emitting unit 140. In other words, the rectifying unit 120 and the light emitting unit 140 are formed on the same substrate (same chip) and have a monolithic structure.

  The capacity adjustment layer 112 may be made of, for example, a GaAs layer that is not doped with impurities, and the first semiconductor layer 114 may be made of, for example, a second conductivity type (for example, p-type) GaAs layer. Therefore, a pin diode is formed by the p-type first semiconductor layer 114, the capacitance adjusting layer 112 not doped with impurities, and the n-type substrate 101.

  The capacity adjustment layer 112 and the first semiconductor layer 114 constitute a columnar semiconductor deposited body (hereinafter referred to as “third columnar portion”) 113. The planar shape of the third columnar portion 113 is, for example, a circle as shown in FIG.

  A substrate connection electrode 118 is electrically connected to the substrate 101, and a first electrode 116 is electrically connected to the first semiconductor layer 114. For example, the substrate connection electrode 118 is formed on the upper surface 101 a of the substrate 101. The planar shape of the substrate connection electrode 118 is, for example, a ring shape as shown in FIG. For example, the first electrode 116 is formed on the first semiconductor layer 114 and on the side of the capacitance reducing layer 122. The planar shape of the first electrode 116 is, for example, a ring shape as shown in FIG. The substrate connection electrode 118 and the first electrode 116 are used to drive the rectifying unit 120.

A capacitance reduction layer 122 is formed on the rectifying unit 120. The capacity reducing layer 122 is provided between the rectifying unit 120 and the light emitting unit 140. Specifically, as shown in FIG. 1, the capacitance reduction layer 122 is provided between the first semiconductor layer 114 and a third contact layer 124 described later. By providing the capacitance reducing layer 122, the parasitic capacitance formed between the first semiconductor layer 114 and the third contact layer 124 can be reduced. As a result, the light emitting unit 140 can be driven at high speed. The material, thickness, and area of the capacitance reducing layer 122 can be appropriately determined according to the size of the parasitic capacitance. As the capacity reduction layer 122, for example, an Al _0.9 Ga _0.1 As layer that is not doped with impurities can be used. Note that the first electrode 116 is formed in a region where the capacitance reducing layer 122 is not formed on the first semiconductor layer 114. Alternatively, the third contact layer 124 can be formed directly on the first semiconductor layer 114 without forming the capacitance reducing layer 122.

The light emitting unit 140 is formed on the capacitance reducing layer 122. The light emitting unit 140 is formed vertically above at least a part of the rectifying unit 120. In other words, in plan view, the outer edge of the lowermost layer (in the present embodiment, the third contact layer 124) of the light emitting unit 140 is the uppermost layer (in the present embodiment, the first semiconductor layer) of the rectifying unit 120. 114) inside the outer edge (including the case where both outer edges coincide). The light emitting unit 140 includes a first conductivity type (for example, n-type) third contact layer 124, a first conductivity type second semiconductor layer 102 formed on the third contact layer 124, and a second semiconductor layer 102. And an active layer 103 formed on the active layer 103 and a third semiconductor layer 104 of the second conductivity type (for example, p-type) formed on the active layer 103. Specifically, the third contact layer 124 is, for example, an n-type GaAs layer. The second semiconductor layer 102 is, for example, 40 pairs of distributed Bragg reflection type (DBR) in which n-type Al _0.9 Ga _0.1 As layers and n-type Al _0.15 Ga _0.85 As layers are alternately stacked. It is a mirror. The active layer 103 has, for example, a multiple quantum well (MQW) structure in which three quantum well structures each composed of a GaAs well layer and an Al _0.3 Ga _0.7 As barrier layer are stacked. The third semiconductor layer 104 is, for example, a 25 pair DBR mirror in which p-type Al _0.9 Ga _0.1 As layers and p-type Al _0.15 Ga _0.85 As layers are alternately stacked. Note that the uppermost layer of the third semiconductor layer 104 may be a contact layer made of, for example, a p-type GaAs layer. In addition, the composition and the number of layers in each of the second semiconductor layer 102, the active layer 103, and the third semiconductor layer 104 are not particularly limited. The p-type third semiconductor layer 104, the active layer 103 not doped with impurities, and the n-type second semiconductor layer 102 form a pin diode.

  The third contact layer 124 and the capacitance reducing layer 122 described above constitute a columnar semiconductor deposited body. The planar shape of the columnar semiconductor deposited body is, for example, a circle. Further, in the light emitting part 140, a part from the third semiconductor layer 104 to the middle of the second semiconductor layer 102 constitutes a columnar semiconductor deposited body (hereinafter referred to as “first columnar part”) 130, and the second The remaining portion of the semiconductor layer 102 constitutes another columnar semiconductor deposited body (hereinafter referred to as “second columnar portion”) 132. The planar shape of the first columnar section 130 is, for example, a circle as shown in FIG. The planar shape of the second columnar part 132 is, for example, a circle having a larger diameter than the circle of the first columnar part 130.

  The light emitting unit 140 includes the oxidized constricting layer 105. For example, the oxidized constricting layer 105 is one of the layers constituting the third semiconductor layer 104. The oxidized constricting layer 105 is formed in a region close to the active layer 103. As the oxidized constricting layer 105, for example, an oxidized AlGaAs layer can be used. The oxidized constricting layer 105 is an insulating layer having an opening. The oxidized constricting layer 105 is formed in a ring shape. More specifically, the oxidized constricting layer 105 has a cross-sectional shape when cut along a plane parallel to the surface 101 a of the substrate 101 shown in FIG. 1 in a ring shape concentric with the planar circular shape of the first columnar portion 130. Is formed.

  The second electrode 107 is formed on the upper surface of the third contact layer 124. The planar shape of the second electrode 107 is, for example, a ring shape as shown in FIG. The second electrode 107 is electrically connected to the third contact layer 124. The third electrode 109 is formed on the first columnar part 130. The planar shape of the third electrode 109 is, for example, a ring shape as shown in FIG. The third electrode 109 is electrically connected to the third semiconductor layer 104. The third electrode 109 has an opening 180 on the first columnar part 130. That is, the opening 180 forms a region where the third electrode 109 is not provided on the upper surface of the third semiconductor layer 104. This region is the laser light emission surface 108. The shape of the emission surface 108 is, for example, a circle as shown in FIG.

  In the surface-emitting type device 100 shown in FIGS. 1 and 2, the second electrode 107 is joined to the second semiconductor layer 102 via the third contact layer 124, and the third electrode 109 is formed on the first columnar part 130. Bonded to the third semiconductor layer 104. A current is injected into the active layer 103 by the second electrode 107 and the third electrode 109.

  As shown in the circuit diagram of FIG. 3, the rectifying unit 120 and the light emitting unit 140 are electrically connected in parallel, and the rectifying unit 120 has a rectifying action in a direction opposite to that of the light emitting unit 140. As a specific connection form, for example, the first electrode 116 and the second electrode 107 are electrically connected by the first wiring 126, and the substrate connection electrode 118 and the third electrode 109 are electrically connected by the second wiring 128. Can be connected to. In addition, illustration of the 2nd wiring 128 is simplified in FIG. 1, and is abbreviate | omitted in FIG.

  When driving the light emitting unit 140, a forward bias voltage is applied to the light emitting unit 140, and a reverse bias voltage is applied to the rectifying unit 120. At this time, it is preferable that the breakdown voltage of the rectifying unit 120 is larger than the driving voltage of the light emitting unit 140 in order to pass a current only through the light emitting unit 140. As a result, even if a forward bias voltage is applied to the light emitting unit 140, no reverse current flows (or hardly flows) through the rectifying unit 120, so that the light emitting unit 140 normally performs a light emitting operation.

  Here, the breakdown voltage of the rectifying unit 120 can be appropriately controlled by adjusting the composition, impurity concentration, and the like of the substrate 101 and the first semiconductor layer 114, for example. For example, if the impurity concentrations of the substrate 101 and the first semiconductor layer 114 are reduced, the breakdown voltage of the rectifying unit 120 can be increased. The substrate 101 and the first semiconductor layer 114 are formed separately from the semiconductor layer that contributes to the light emitting operation of the light emitting unit 140. Therefore, the composition and impurity concentration of the substrate 101 and the first semiconductor layer 114 can be freely adjusted. Accordingly, the rectifying unit 120 having more ideal characteristics can be easily formed, and effective prevention of electrostatic breakdown and more stable light emitting operation can be realized.

  Alternatively, the driving voltage of the light emitting unit 140 can be made smaller than the breakdown voltage of the rectifying unit 120 by adjusting the composition and impurity concentration of the second and third semiconductor layers 102 and 104 of the light emitting unit 140.

  In addition, by changing the film thickness of the capacity adjustment layer 112, the capacity of the rectifying unit 120 can be changed and set to a desired value as appropriate. For example, by reducing the thickness of the capacitance adjustment layer 112, the capacitance of the rectifying unit 120 can be increased, and as a result, the breakdown voltage of the rectifying unit 120 can be increased.

  The present invention is not limited to the case where the light emitting unit 140 is a surface emitting semiconductor laser, and can be applied to other surface emitting devices (for example, semiconductor light emitting diodes and organic LEDs). In addition, the present invention is not limited to the case where the rectifying unit 120 is a junction diode, and can be applied to other rectifying elements (for example, Schottky diodes).

  1-2. Next, an example of a method for manufacturing the surface-emitting type device 100 according to the present embodiment will be described with reference to FIGS. 1, 2, 4, and 5. 4 and 5 are cross-sectional views schematically showing one manufacturing process of the surface-emitting type device 100 of the present embodiment shown in FIGS. 1 and 2, and each correspond to the cross-sectional view shown in FIG.

  (1) First, as shown in FIG. 4, for example, an n-type GaAs substrate is prepared as the substrate 101.

  Next, the semiconductor multilayer film 150 is formed on the substrate 101 by epitaxial growth while modulating the composition. The semiconductor multilayer film 150 includes semiconductor layers constituting the capacitance adjustment layer 112, the first semiconductor layer 114, the capacitance reduction layer 122, the third contact layer 124, the second semiconductor layer 102, the active layer 103, and the third semiconductor layer 104. They are laminated in order. Note that when the third semiconductor layer 104 is grown, at least one layer in the vicinity of the active layer 103 can be a layer that is oxidized later to become the oxidized constricting layer 105. As the layer that becomes the oxidized constricting layer 105, for example, an AlGaAs layer having an Al composition of 0.95 or more can be used. The Al composition of the AlGaAs layer is the composition of aluminum (Al) with respect to the group III element.

  (2) Next, as shown in FIG. 5, the semiconductor multilayer film 150 is patterned to have a desired shape of the capacitance adjusting layer 112, the first semiconductor layer 114, the capacitance reducing layer 122, the third contact layer 124, and the second semiconductor. The layer 102, the active layer 103, and the third semiconductor layer 104 are formed. Thereby, the 1st-3rd columnar part 130,132,113 is formed. The patterning of the semiconductor multilayer film 150 can be performed by a known lithography technique and etching technique.

  Next, as shown in FIG. 5, the above-described oxidation is performed by introducing the substrate 101 on which the first to third columnar portions 130, 132, 113 are formed by the above-described process in a water vapor atmosphere of about 400 ° C., for example. The layer that becomes the constricting layer 105 is oxidized from the side surface to form the oxidized constricting layer 105. In the light emitting unit 140 having the oxidized constricting layer 105, when driven, a current flows only in a portion where the oxidized constricting layer 105 is not formed (a portion not oxidized). Therefore, in the step of forming the oxidized constricting layer 105, the current density can be controlled by controlling the range of the oxidized constricting layer 105 to be formed.

  (3) Next, as shown in FIGS. 1 and 2, the substrate connection electrode 118, the first to third electrodes 116, 107, 109, and the first and second wirings 126, 128 are formed. These electrodes and wiring can be formed by, for example, a combination of a vacuum deposition method and a lift-off method. As the substrate connection electrode 118 and the second electrode 107, for example, an alloy of gold (Au) and germanium (Ge), a stacked film of nickel (Ni), and gold (Au) can be used. As the first electrode 116 and the third electrode 109, for example, an alloy of gold (Au) and zinc (Zn) and a laminated film of gold (Au) can be used. As the first and second wirings 126 and 128, for example, gold (Au) can be used. Note that the order of forming each electrode and each wiring is not particularly limited.

  Through the above steps, as shown in FIGS. 1 and 2, the surface-emitting type device 100 of the present embodiment is obtained.

  1-3. Next, a modified example of the surface emitting device 100 according to the present embodiment will be described with reference to the drawings. Note that differences from the surface-emitting type device 100 shown in FIGS. 1 and 2 described above will be described, and description of similar points will be omitted. 6 is a cross-sectional view taken along the line VI-VI in FIG. 7, and FIG. 7 is a plan view schematically showing an example of a modification of the surface-emitting type device 100.

  For example, as shown in FIG. 6, the substrate connection electrode 118 can be formed on the entire back surface 101 b of the substrate 101. In the surface-emitting type device 100 shown in FIGS. 1 and 2, the first and second electrodes 116 and 107 and the first wiring 126 surround the second columnar section 132. For example, as shown in FIG. In addition, the first and second electrodes 116 and 107 and the first wiring 126 may be formed on a part of the side of the second columnar portion 132 without surrounding the second columnar portion 132. The planar shapes of the first and second electrodes 116 and 107 and the first wiring 126 can be rectangular as shown in FIG. 7, for example.

  In addition, the modification mentioned above is an example, Comprising: It is not necessarily limited to this.

  1-4. According to the surface-emitting type device 100 according to the present embodiment, even when a reverse bias voltage is applied to the light emitting unit 140, a current flows through the rectifying unit 120 connected in parallel with the light emitting unit 140. Thereby, the electrostatic breakdown voltage against the reverse bias voltage of the surface emitting device 100 can be remarkably improved. Therefore, electrostatic breakdown in the mounting process or the like can be prevented, so that handling is excellent and reliability can be improved.

  In addition, according to the surface emitting device 100 according to the present embodiment, the light emitting unit 140 is formed vertically above a part of the rectifying unit 120. In other words, a part of the rectifying unit 120 is disposed immediately below the light emitting unit 140. That is, the space immediately below the light emitting unit 140 can be used effectively. For example, as shown in FIGS. 1 and 2, a rectifying unit 120 having a plane area comparable to the area of the light emitting unit 140 in plan view (hereinafter referred to as “planar area”) is provided below the light emitting unit 140. it can. As a result, for example, compared to the case where the rectifying unit 120 is formed on the side of the light emitting unit 140, the planar area of the entire device can be reduced. In this case, the plane area of the entire surface emitting device 100 is approximately the same as the plane area of the light emitting unit 140. Accordingly, in order to drive the light emitting unit 140 at a higher speed, the planar area of the surface emitting device 100 is reduced as the planar area of the light emitting unit 140 is reduced and the capacity of the light emitting unit 140 itself is reduced. be able to. That is, according to this embodiment, the plane area of the entire device can be made independent of the plane area of the rectifying unit 120.

  Further, for example, as shown in FIGS. 6 and 7, the plane area of the rectifying unit 120 can be freely increased as necessary as compared with the plane area of the light emitting unit 140. By increasing the plane area of the rectifying unit 120, the capacity can be increased, and the breakdown voltage can be increased. Also in this case, the plane area of the light emitting unit 140 can be freely reduced as necessary. By reducing the plane area of the light emitting unit 140, the capacity can be reduced, and as a result, the light emitting unit 140 can be driven at high speed.

2. Second embodiment 2-1. Next, a surface emitting device 200 according to the second embodiment will be described. In addition, it demonstrates centering on a different point from the surface emitting type apparatus 100 shown in FIG. 1 and FIG. 2 mentioned above, and abbreviate | omits description about the same point.

  8 is a cross-sectional view taken along the line VIII-VIII in FIG. 9, and FIG. 9 is a plan view schematically showing the surface-emitting type device 200. As shown in FIG. The same members as those in the surface-emitting type device 100 shown in FIGS. 1 and 2 are given the same reference numerals.

  As shown in FIGS. 8 and 9, the surface light emitting device 200 includes a rectifying unit 120, a light emitting unit 140, and a light detecting unit 170. In the present embodiment, a case will be described in which the rectifying unit 120 functions as a junction diode (including a Zener diode), the light emitting unit 140 functions as a surface emitting semiconductor laser, and the light detection unit 170 functions as a photodiode.

  The rectifying unit 120 is formed above the substrate 101, the fourth semiconductor layer 111 formed above the substrate 101, the capacitance adjustment layer 112 formed above the fourth semiconductor layer 111, and the capacitance adjustment layer 112. And a first semiconductor layer 114. As the substrate 101, for example, a semi-insulating GaAs substrate can be used. The substrate 101 supports the rectifying unit 120, the light emitting unit 140, and the light detecting unit 170. In other words, the rectifying unit 120, the light emitting unit 140, and the light detecting unit 170 are formed on the same substrate (same chip) and have a monolithic structure.

  The fourth semiconductor layer 111 can be made of, for example, a first conductivity type (eg, n-type) GaAs layer. Therefore, a pin diode is formed by the p-type first semiconductor layer 114, the capacitance adjusting layer 112 not doped with impurities, and the n-type fourth semiconductor layer 111.

  A fourth electrode 119 is electrically connected to the fourth semiconductor layer 111. For example, the fourth electrode 119 is formed on the fourth semiconductor layer 111. The planar shape of the fourth electrode 119 is, for example, a ring shape as shown in FIG. The fourth electrode 119 and the first electrode 116 are used to drive the rectifying unit 120.

  The rectifying unit 120 and the light emitting unit 140 are electrically connected in parallel, and the rectifying unit 120 has a rectifying action in the opposite direction to the light emitting unit 140. As a specific connection form, for example, the first electrode 116 and the second electrode 107 are electrically connected by the first wiring 126, and the third electrode 109 and the fourth electrode 119 are electrically connected by the second wiring 128. Can be connected to. In addition, illustration of the 2nd wiring 128 is simplified in FIG. 8, and is abbreviate | omitted in FIG.

  The light detection unit 170 includes a substrate 101, a second contact layer (above-mentioned “other contact layer”) 171 formed above the substrate 101, and a light absorption layer 172 formed above the second contact layer 171. And a first contact layer (“contact layer” described above) 174 formed above the light absorption layer 172. The second contact layer 171 is formed in the same step as the fourth semiconductor layer 111, the light absorption layer 172 is formed in the same step as the capacitance adjustment layer 112, and the first contact layer 174 is formed in the first step. 1 semiconductor layer 114 is formed in the same process. In other words, the second contact layer 171 is made of a semiconductor having the same composition as that of the fourth semiconductor layer 111, the light absorption layer 172 is made of a semiconductor having the same composition as that of the capacitance adjustment layer 112, and the first contact layer 174 is made of the first contact layer 174. The semiconductor layer 114 is made of a semiconductor having the same composition. The distance between the substrate 101 and the light absorption layer 172 is approximately the same as the distance between the substrate 101 and the capacitance adjustment layer 112, and the distance between the substrate 101 and the first contact layer 174 is equal to the distance between the substrate 101 and the first semiconductor layer. It is about the same as the distance to 114.

  Specifically, the second contact layer 171 is made of, for example, a first conductivity type (for example, n-type) GaAs layer, and the light absorption layer 172 is made of, for example, a GaAs layer not doped with impurities, and the first contact layer 174 is made. Can comprise, for example, a second conductivity type (eg, p-type) GaAs layer. Therefore, the p-type first contact layer 174, the light absorption layer 172 not doped with impurities, and the n-type second contact layer 171 form a pin diode.

  The planar shape of the second contact layer 171 is, for example, a ring shape surrounding the fourth semiconductor layer 111. The first contact layer 174 and the light absorption layer 172 constitute a columnar semiconductor deposited body (hereinafter referred to as “fourth columnar portion”) 173. The planar shape of the fourth columnar portion 173 is, for example, a ring shape. The inner side surface of the fourth columnar portion 173 is continuous with the inner side surface of the second contact layer 171.

  A fifth electrode 176 is electrically connected to the first contact layer 174, and a sixth electrode 178 is electrically connected to the second contact layer 171. For example, the fifth electrode 176 is formed on the periphery of the first contact layer 174. The planar shape of the fifth electrode 176 is, for example, a ring shape as shown in FIG. For example, the sixth electrode 178 is formed on the second contact layer 171. The planar shape of the sixth electrode 178 is, for example, a ring shape as shown in FIG. The fifth and sixth electrodes 176 and 178 are used to drive the light detection unit 170.

  On the first contact layer 174, a damming member 177 and a lens portion 179 are formed. For example, the blocking member 177 is formed on the periphery of the first contact layer 174. The planar shape of the damming member 177 is, for example, a ring shape as shown in FIG. Of the upper surface of the first contact layer 174, a region where the blocking member 177 and the fifth electrode 176 are not formed is a light incident surface 175. The shape of the light incident surface 175 is, for example, a ring shape as shown in FIG. 9 in a plan view. Note that, when a material that transmits light is used as the damming member 177, the region where the damming member 177 is formed is also the light incident surface 175. By providing the blocking member 177, in the process of forming the lens portion 179, the material of the lens portion 179 is blocked and the lens portion 179 can be formed in a desired shape. The lens unit 179 can be formed at least on the light incident surface 175. The lens part 179 can have a convex shape as shown in FIG. 8, for example. As the lens portion 179, an ultraviolet curable resin, a thermosetting resin, or the like can be used. As shown in FIG. 8, the lens unit 179 can cause light (arrow A) emitted from the side surface of the active layer 103 to enter the incident surface 175 of the light detection unit 170. Details will be described later.

  An element isolation region 181 is formed between the rectifying unit 120 and the light emitting unit 140 and the light detecting unit 170. Specifically, the element isolation region 181 can be a groove constituted by, for example, the side surface of the fourth semiconductor layer 111, the upper surface of the substrate 101, and the side surface of the second contact layer 171. That is, this groove can be dug up to a depth at least where the upper surface of the substrate 101 is exposed. In this case, by using an insulating or semi-insulating substrate for the substrate 101, the rectifying unit 120, the light emitting unit 140, and the light detecting unit 170 can be reliably electrically separated. The planar shape of the element isolation region 181 is, for example, a ring shape.

  2-2. Next, an example of a method for manufacturing the surface-emitting type device 200 according to the present embodiment will be described with reference to FIGS. In addition, it demonstrates centering on a different point from the manufacturing method of the surface emitting type apparatus 100 shown in FIG. 1 and FIG. 2 mentioned above, and abbreviate | omits description about the same point.

  FIGS. 10 and 11 are cross-sectional views schematically showing one manufacturing process of the surface-emitting type device 200 of the present embodiment shown in FIGS. 8 and 9, and each correspond to the cross-sectional view shown in FIG.

  (1) First, as shown in FIG. 10, for example, a semi-insulating GaAs substrate is prepared as the substrate 101.

  Next, the semiconductor multilayer film 150 is formed on the substrate 101 by epitaxial growth while modulating the composition. The semiconductor multilayer film 150 includes a fourth semiconductor layer 111 (second contact layer 171), a capacitance adjustment layer 112 (light absorption layer 172), a first semiconductor layer 114 (first contact layer 174), a capacitance reduction layer 122, a third layer. The contact layer 124, the second semiconductor layer 102, the active layer 103, and the semiconductor layers constituting the third semiconductor layer 104 are sequentially stacked. Here, the semiconductor layer constituting the fourth semiconductor layer 111 is also a semiconductor layer constituting the second contact layer 171, and the semiconductor layer constituting the capacitance adjusting layer 112 is also a semiconductor layer constituting the light absorption layer 172. The semiconductor layer constituting the first semiconductor layer 114 is also a semiconductor layer constituting the first contact layer 174.

  (2) Next, as shown in FIG. 11, the semiconductor multilayer film 150 is patterned, and the desired shape of the fourth semiconductor layer 111 and the second contact layer 171, the capacitance adjustment layer 112 and the light absorption layer 172, the first semiconductor The layer 114, the first contact layer 174, the capacitance reducing layer 122, the third contact layer 124, the second semiconductor layer 102, the active layer 103, and the third semiconductor layer 104 are formed. Here, the fourth semiconductor layer 111 and the second contact layer 171 can be formed in the same patterning process, and the capacitance adjusting layer 112 and the light absorption layer 172 can be formed in the same patterning process. The one semiconductor layer 114 and the first contact layer 174 can be formed in the same patterning process. Further, when the fourth semiconductor layer 111 and the second contact layer 171 are formed, the element isolation region 181 can be formed therebetween. Next, as shown in FIG. 11, an oxidized constricting layer 105 is formed.

  (3) Next, as shown in FIGS. 8 and 9, first to sixth electrodes 116, 107, 109, 119, 176, 178 and first and second wirings 126, 128 are formed. As the fourth and sixth electrodes 119 and 178, for example, an alloy of gold (Au) and germanium (Ge), a stacked film of nickel (Ni), and gold (Au) can be used. As the sixth electrode 176, for example, an alloy of gold (Au) and zinc (Zn) and a stacked film of gold (Au) can be used.

  Next, as shown in FIGS. 8 and 9, a damming member 177 is formed on the first contact layer 174. As the damming member 177, for example, a resin such as polyimide or a dielectric layer such as SiN can be used. The damming member 177 can be formed by, for example, a spin coating method, a CVD (Chemical Vapor Deposition) method, or the like. The damming member 177 can be patterned using, for example, a known lithography technique and etching technique.

  Next, as shown in FIGS. 8 and 9, a lens portion 179 is formed on at least the incident surface 175. As shown in FIG. 8, the lens unit 179 is formed so that light (arrow A) emitted from the side surface of the active layer 103 can be incident on the incident surface 175 of the light detection unit 170. The lens unit 179 can be formed by, for example, a dispenser method, an inkjet method, or the like.

  Through the above steps, as shown in FIGS. 8 and 9, the surface-emitting type device 200 of the present embodiment is obtained.

  2-3. The surface-emitting type device 200 according to the present embodiment has substantially the same operations and effects as the operations and effects described in the first embodiment.

  Further, in the surface-emitting type device 200 according to the present embodiment, as described above, the lens unit 179 causes the light (arrow A) emitted from the side surface of the active layer 103 to be a light detection unit as illustrated in FIG. It is possible to make the light incident on an incident surface 175 of 170. Specifically, it is as follows.

  In the light emitting unit 140, when a forward bias voltage of a pin diode is applied to the second and third electrodes 107 and 109, recombination of electrons and holes occurs in the active layer 103, and light emission due to such recombination occurs. Most of the generated light is stimulated emission when reciprocating between the second semiconductor layer 102 and the third semiconductor layer 104, and the light intensity is amplified. When the optical gain exceeds the optical loss, laser oscillation occurs, and laser light is emitted from the emission surface 108 in a direction perpendicular to the substrate 101. On the other hand, by adjusting the reflectance of light on the side surface of the active layer 103 (less than 100%), a part of the light generated in the active layer 103 can be emitted from the side surface of the active layer 103. The light reflectance on the side surface of the active layer 103 can be adjusted, for example, by appropriately selecting a member that covers the side surface of the active layer 103. Light (arrow A) emitted from the side surface of the active layer 103 is refracted by the lens unit 179. This refracted light (arrow B) is reflected on the outer peripheral surface of the lens portion 179. The reflected light (arrow C) is incident on the incident surface 175 of the light detection unit 170 as shown in FIG. As a result, the light detection unit 170 can detect light emitted from the side surface of the active layer 103.

  That is, the light detection unit 170 according to the present embodiment can monitor a part of the light output of the light emitting unit 140 that functions as a surface emitting semiconductor laser. In other words, the light detection unit 170 can function as a monitor photodiode for a surface emitting semiconductor laser. By feeding back the monitored result to the drive circuit, output fluctuation due to temperature or the like can be corrected, so that stable light output can be obtained.

  Note that the light detection unit 170 can also function as, for example, a receiving photodiode for bidirectional optical communication. In this case, the light detection unit 170 can function as a monitor photodiode for the surface-emitting type semiconductor laser described above, or can not function. When it does not function, the lens portion 179 can be omitted.

  In addition, according to the surface emitting device 200 and the manufacturing method thereof according to the present embodiment, the second contact layer 171 is formed in the same process as the fourth semiconductor layer 111, and the light absorption layer 172 is the capacitance adjustment layer 112. The first contact layer 174 can be formed in the same process as the first semiconductor layer 114. Therefore, when the rectifying unit 120, the light emitting unit 140, and the light detecting unit 170 are formed on the same substrate, the manufacturing process can be simplified. That is, according to the surface emitting device 200 and the manufacturing method thereof according to the present embodiment, the rectifying unit 120, the light emitting unit 140, and the light detecting unit 170 can be easily integrated on the same substrate.

  Further, according to the surface-emitting type device 200 according to the present embodiment, the light emitting unit 140 for transmitting bidirectional optical communication and the light detecting unit 170 for receiving can be formed on the same substrate. The alignment process with the optical waveguide (for example, optical fiber etc.) used for optical communication can be simplified. As a result, the manufacturing cost can be reduced.

  As described above, the embodiments of the present invention have been described in detail. However, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. . Accordingly, all such modifications are intended to be included in the scope of the present invention.

  For example, in the surface emitting devices 100 and 200 according to the above-described embodiments, the case where the light emitting unit 140 has one first columnar part 130 has been described. However, the light emitting unit 140 includes a plurality of first columnar parts 130. Even if the first columnar portion 130 is not formed in the step of patterning the semiconductor multilayer film 150, the embodiment of the present invention is not impaired. Further, in the step of patterning the semiconductor multilayer film 150, the light detection unit 170 may be divided into a plurality of electrically separated light detection units. Further, even when the plurality of surface emitting devices 100 and 200 are arrayed, the same operation and effect can be achieved. Further, for example, in the above-described embodiment, even if the p-type and the n-type in each semiconductor layer are switched, it does not depart from the spirit of the present invention.

1 is a cross-sectional view schematically showing a surface-emitting type device according to a first embodiment. The top view which shows typically the surface emitting type apparatus which concerns on 1st Embodiment. 1 is a circuit diagram of a surface-emitting type device according to a first embodiment. Sectional drawing which shows typically the manufacturing method of the surface emitting type apparatus which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the surface emitting type apparatus which concerns on 1st Embodiment. Sectional drawing which shows typically the modification of the surface emitting type apparatus which concerns on 1st Embodiment. The top view which shows typically the modification of the surface emitting type apparatus which concerns on 1st Embodiment. Sectional drawing which shows the surface emitting type apparatus which concerns on 2nd Embodiment typically. The top view which shows typically the surface emitting type apparatus which concerns on 2nd Embodiment. Sectional drawing which shows typically the manufacturing method of the surface emitting type apparatus which concerns on 2nd Embodiment. Sectional drawing which shows typically the manufacturing method of the surface emitting type apparatus which concerns on 2nd Embodiment.

Explanation of symbols

100 surface emitting device, 101 substrate, 102 second semiconductor layer, 103 active layer, 104 third semiconductor layer, 105 oxidized constriction layer, 107 second electrode, 108 exit surface, 109 third electrode, 111 fourth semiconductor layer, 112 capacitance adjusting layer, 113 third columnar portion, 114 first semiconductor layer, 116 first electrode, 118 substrate connection electrode, 119 fourth electrode, 120 rectifier, 122 capacitance reducing layer, 124 third contact layer, 126 first Wiring, 128 second wiring, 130 first columnar section, 132 second columnar section, 140 light emitting section, 150 semiconductor multilayer film, 170 light detection section, 171 second contact layer, 172 light absorption layer, 173 fourth columnar section, 174 First contact layer, 175 incident surface, 176 fifth electrode, 177 damming member, 178 sixth electrode, 179 lens portion, 18 0 opening, 181 element isolation region, 200 surface emitting device

Claims (11)

A rectifying unit including a substrate and a first semiconductor layer formed above the substrate;
A first conductivity type second semiconductor layer formed above the rectifying unit; an active layer formed above the second semiconductor layer; and a second conductivity type second semiconductor layer formed above the active layer. A light emitting unit including three semiconductor layers,
The rectifying unit and the light emitting unit are electrically connected in parallel,
The rectification section is to have a rectification action in a reverse direction with respect to the light emitting portion,
A surface-emitting type device having a light detection unit including the substrate, a light absorption layer formed above the substrate, and a contact layer formed above the light absorption layer . Oite to claim 1,
A substrate connection electrode electrically connected to the substrate;
First, second, and third electrodes that are electrically connected to the first, second, and third semiconductor layers, respectively.
The substrate is of a first conductivity type;
The first semiconductor layer is of a second conductivity type;
The substrate connection electrode and the third electrode are electrically connected,
The surface emitting device, wherein the first electrode and the second electrode are electrically connected. A rectifying unit including a substrate and a first semiconductor layer formed above the substrate;
A first conductivity type second semiconductor layer formed above the rectifying unit; an active layer formed above the second semiconductor layer; and a second conductivity type second semiconductor layer formed above the active layer. A light emitting unit including three semiconductor layers,
The rectifying unit and the light emitting unit are electrically connected in parallel,
The rectification section is to have a rectification action in a reverse direction with respect to the light emitting portion,
The rectifying unit includes a fourth semiconductor layer formed between the substrate and the first semiconductor layer,
Having first, second, third, and fourth electrodes electrically connected to the first, second, third, and fourth semiconductor layers, respectively;
The first semiconductor layer is of a second conductivity type;
The fourth semiconductor layer is of a first conductivity type;
The first electrode and the second electrode are electrically connected,
The surface emitting device , wherein the third electrode and the fourth electrode are electrically connected . Oite to claim 3,
A light detection unit including the substrate, a light absorption layer formed above the substrate, and a contact layer formed above the light absorption layer;
The light detection unit has another contact layer formed between the substrate and the light absorption layer,
The contact layer is formed in the same process as the first semiconductor layer,
The other contact layer is a surface-emitting type device formed in the same process as the fourth semiconductor layer. A rectifying unit including a substrate and a first semiconductor layer formed above the substrate;
A first conductivity type second semiconductor layer formed above the rectifying unit; an active layer formed above the second semiconductor layer; and a second conductivity type second semiconductor layer formed above the active layer. A light emitting unit including three semiconductor layers;
Including
The rectifying unit and the light emitting unit are electrically connected in parallel,
The rectification section is to have a rectification action in a reverse direction with respect to the light emitting portion,
The rectifying unit includes a fourth semiconductor layer formed between the substrate and the first semiconductor layer,
A light detection unit including the substrate, a light absorption layer formed above the substrate, and a contact layer formed above the light absorption layer;
The light detection unit has another contact layer formed between the substrate and the light absorption layer,
The contact layer is formed in the same process as the first semiconductor layer,
The other contact layer is a surface-emitting type device formed in the same process as the fourth semiconductor layer . In any one of Claims 1-5 ,
A surface-emitting device in which a capacitance adjusting layer is formed between the substrate and the first semiconductor layer. In any one of Claims 1-6 ,
The light emitting unit is a surface-emitting type device that is formed vertically above at least a part of the rectifying unit. In any of the claims 1-7,
The light emitting unit functions as a surface emitting semiconductor laser,
The surface emitting device, wherein the second semiconductor layer and the third semiconductor layer are mirrors. In claim 1, 2, 4, or 5 ,
The light emitting unit functions as a surface emitting semiconductor laser,
The second semiconductor layer and the third semiconductor layer are mirrors;
The light detection unit functions as a monitor photodiode for the surface emitting semiconductor laser,
A surface-emitting type device in which a lens portion is formed above the contact layer. Forming a first semiconductor layer above the substrate; forming a first conductivity type second semiconductor layer above the first semiconductor layer; and forming an active layer above the second semiconductor layer. Forming a semiconductor multilayer film, comprising: a step; forming a second conductive type third semiconductor layer above the active layer;
The semiconductor is formed such that a rectifying unit including the substrate and the first semiconductor layer, and a light emitting unit including the second semiconductor layer, the active layer, and the third semiconductor layer are formed. Patterning the multilayer film, and
The rectifying unit and the light emitting unit are arranged to be electrically connected in parallel,
The rectifying unit is formed to have a rectifying action in the opposite direction to the light emitting unit,
In the step of forming the semiconductor multilayer film,
Forming a contact layer in the same process as the first semiconductor layer;
The step of forming the semiconductor multilayer film includes the step of forming a light absorption layer above the substrate before the step of forming the contact layer,
The step of patterning the semiconductor multilayer film includes:
A method for manufacturing a surface-emitting device , wherein the light-detecting unit including the substrate, the light absorption layer, and the contact layer is formed . Forming a first semiconductor layer above the substrate; forming a first conductivity type second semiconductor layer above the first semiconductor layer; and forming an active layer above the second semiconductor layer. Forming a semiconductor multilayer film, comprising: a step; forming a second conductive type third semiconductor layer above the active layer;
The semiconductor is formed such that a rectifying unit including the substrate and the first semiconductor layer, and a light emitting unit including the second semiconductor layer, the active layer, and the third semiconductor layer are formed. Patterning the multilayer film, and
The rectifying unit and the light emitting unit are arranged to be electrically connected in parallel,
The rectifying unit is formed to have a rectifying action in the opposite direction to the light emitting unit,
The step of forming the semiconductor multilayer film includes a step of forming a fourth semiconductor layer above the substrate before the step of forming the first semiconductor layer,
The step of patterning the semiconductor multilayer film includes:
The rectification unit having the fourth semiconductor layer is formed,
In the step of forming the semiconductor multilayer film,
Forming a contact layer in the same process as the first semiconductor layer;
Forming another contact layer in the same process as the fourth semiconductor layer;
The step of forming the semiconductor multilayer film includes a step of forming a light absorption layer above the other contact layer before the step of forming the contact layer,
The step of patterning the semiconductor multilayer film includes:
A method for manufacturing a surface-emitting type device, wherein the method is performed so that a light detection unit including the contact layer, the light absorption layer, and the other contact layer is formed .

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